Introduction: What Is Sociobiology?

I was surprised--even astonished--by the initial reaction toSociobiology: The New Synthesis (1975a). When the book waspublished in 1975, I expected a favorable reaction from otherbiologists. After all, my colleagues and I had merely been extendingneo-Darwinism into the study of social behavior and animal societies,and the underlying biological principles we employed were largelyconventional. The response was in fact overwhelmingly favorable. Fromthe social scientists, I expected not much reaction. I took it forgranted that the human species is subject to sociobiological analysisno less than to genetic or endocrinological analysis; the finalchapter of my book simply completed the catalogue of social speciesby adding Homo sapiens. I hoped to make a contribution to thesocial sciences and humanities by laying out, in immediatelyaccessible form, the most relevant methods and principles ofpopulation biology, evolutionary theory, and sociobiology. I expectedthat many social scientists, already convinced of the necessity of abiological foundation for their subject, would be tempted to pick upthe tools and try them out. This has occurred to a limited extent,but there has also been stiff resistance. I now understand that Ientirely underestimated the Durkheim-Boas tradition of autonomy ofthe social sciences, as well as the strength and power of theantigenetic bias that has prevailed as virtual dogma since the fallof Social Darwinism.

I did not even think about the Marxists. When the attacks onsociobiology came from Science for the People, the leading radicalleft group within American science, I was unprepared for a largelyideological argument. It is now clear to me that I was tampering withsomething fundamental: mythology. Evolutionary theory applied tosocial systems is an extension of the great Western traditions ofscientific materialism. As such, it threatens to transform intotestable hypotheses the assumptions about human nature made by someMarxist philosophers. Its first line of evidence is not favorable tothose assumptions, insofar as most traditional Marxists cling to avision of human nature as a relatively unstructured phenomenon sweptalong by economic forces extraneous to human biology. Marxism andother secular ideologies previously rested secure as unchallengedsatrapies of scientific materialism; now they were in danger of beingdisplaced by other, less manageable biological explanations. Theremarkably harsh response of Science for the People is an example ofwhat Hans Kung (1976) has called the fully of the theologians.

But much of the confusion has come from a simple misunderstandingof the content of sociobiology. Sociobiology is defined as thesystematic study of the biological basis of all forms of socialbehavior, including sexual and parental behavior, in all kinds oforganisms including humans. As such, it is a discipline--aninevitable discipline, since there must be a systematic study ofsocial behavior. Sociobiology consists mostly of zoology. About 90percent of its current material concerns animals, even though over 90percent of the attention given to sociobiology by nonscientists, andespecially journalists, is due to its possible applications to thestudy of human social behavior. There is nothing unusual aboutderiving principles and methods, and even terminology, from intensiveexaminations of lower organisms and applying them to the study ofhuman beings. Most of the fundamental principles of genetics andbiochemistry applied to human biology are based on colon bacteria,fruit flies, and white rats. To say that the same science can beapplied to human beings is not to reduce humanity to the status ofthese simpler creatures.

Nor is there anything new or surprising about having such adiscipline within the family of the biological sciences. The termsociobiology was used independently by John P. Scott in 1946and by Charles F. Hockett in 1948, but the word was not picked upimmediately by others. In 1950, Scott, who had been serving assecretary of the small but influential Committee for the Study ofAnimal Behavior, suggested sociobiology more formally as aterm for the "interdisciplinary science which lies between the fieldsof biology (particularly ecology and physiology) and psychology andsociology" (p. 1004). From 1956 to 1964, Scott and others constitutedthe Section on Animal Behavior and Sociobiology of the EcologicalSociety of America. This Section became the present Animal BehaviorSociety. During 1950-1970, sociobiology was employed intermittentlyin technical articles, a usage evidently inspired by its alreadyquasi-official status. But other expressions, such asbiosociology and animal sociology, were also employed.When I wrote the final chapter of The Insect Societies (1971),which was entitled "The Prospect for a Unified Sociobiology" and whenI wrote Sociobiology: The New Synthesis (1975a), where Isuggested that a discrete discipline should now be built on afoundation of genetics and population biology, I selected the termsociobiology rather than some other, novel expression becauseI believed it would already be familiar to most students of animalbehavior and hence more likely to be accepted.

Pure sociobiological theory, being independent of human biology,does not imply by itself that human social behavior is determined bygenes. It allows for any one of three possibilities. One is that thehuman brain has evolved to the point that it has become anequipotential learning machine entirely determined by culture. Themind, in other words, has been freed from the genes. A secondpossibility is that human social behavior is under genetic constraintbut that all of the genetic variability within the human species hasbeen exhausted. Hence our behavior is to some extent influenced bygenes, but we all have exactly the same potential. A thirdpossibility, close to the second, is that the human species isprescribed to some extent but also displays some genetic differencesamong individuals. As a consequence, human populations retain thecapacity to evolve still further in their biological capacity forsocial behavior.

I consider it virtually certain that the third alternative is thecorrect one. Because the evidence has been well reviewed in otherrecent works, most notably Chagnon and Irons (Eds., in press), DeVore (in press), and Freedman (in press), I will not undertake toexemplify it or review it in detail. Instead, let me outline itscontent.

1. Specificity of human social behavior. Although thevariation of cultures appears enormous to the anthropocentricobserver, all human behavior together comprises only a tiny subset ofthe realized social systems of the thousands of social species onearth. Corals and other colonial invertebrates, the social insects,fish, birds, and nonhuman mammals display among themselves an arrayof' arrangements that it is difficult for human beings even tounderstand, much less imitate. Even if we were to attempt toduplicate some of these social behaviors by conscious design, itwould be a charade likely to create emotional breakdown and a rapidreversal of the effort.

2. Phylogenetic relationships. Our social arrangements mostclosely resemble those of the Old World monkeys and apes, which onanatomical and biochemical grounds are our closest living relatives.This is the result expected if we share a common ancestry with theseprimates, which appears to be an established fact, and if humansocial behavior is still constrained to some extent by geneticpredispositions in behavioral development.

3. Conformity to sociobiological theory. In the case of thehypothesis of genetic constraints on human social behavior, it shouldbe possible to select some of the best principles of populationgenetics and ecology, which form the foundations of sociobiology, andto apply them in detail to the explanations of human socialorganization. The hypothesis should then not only account for many ofthe known facts in a more convincing manner than do previous attemptsbut should also identify the need for new kinds of' information notconceptualized by the unaided social sciences. The behavior thusexplained should be the most general and least rational of the humanrepertory, the furthest removed from the influence of year-by-yearshifts in fashion and convention. There are in fact a substantialnumber of anthropological studies completed or underway that meetthese exacting criteria of postulational-deductive science. Amongthem can be cited the work of Joseph Shepher (1971) on the incesttaboo and sexual roles, Mildred Dickeman (in press) on hypergamy andsex-biased infanticide, William Irons (in press) on the relationbetween inclusive genetic fitness and the local set of evaluationalcriteria of social success in a herding society, Napoleon Chagnon(1976) on aggression and reproductive competition in the Yanomamo,William Durham (1976) on the relation between inclusive fitness andwarfare in the Mundurucu and other primitive societies, Robin Fox(personal communication) on the relation of fitness to kinship rules,Melvin Konner (1972) and Daniel G. Freedman (1974, in press) on theadaptive significance of infant development, and James Weinrich(1977) on the relationship of genetic fitness and the details ofsexual practice, including homosexuality.

4. Genetic variation within the species. By 1977, more than1,200 loci had been located on human chromosomes through the fineanalysis of biochemical and other mutations (McKusick and Ruddle,1977). Many of these point mutations, as well as a growing list ofchromosomal aberrations, affect behavior. Most simply diminish mentalcapacity and motor ability, but at least two, the Lesch-Nyhansyndrome, based on a single gene, and Turner's syndrome, caused bythe deletion of a sex chromosome, alter behavior in narrow ways thatcan be related to specific neuromuscular mechanisms. Theadrenogenital syndrome, which is induced by a single recessive gene,appears to masculinize girls through an early induction ofadrenocortical substances that mimic the male hormone.

More complex forms of human behavior are almost certainly underthe control of polygenes (genes scattered on many chromosome loci),which in turn create their effects through alternating a wide arrayof mediating devices, from elementary neuronal wiring to muscularcoordination and "mental set" induced by hormone levels. In mostinstances, the role of behavioral polygenes can be evaluated--butonly qualitatively--by the careful application of twin and adoptionstudies. The most frequently used method is to compare the similaritybetween identical twins, who are known to be genetically identical,with the similarity between fraternal twins, who are no closergenetically than ordinary siblings. When the similarity betweenidentical twins proves greater, this distinction between the twokinds of twins is ascribed to heredity. Using this and relatedtechniques, geneticists have found evidence of a substantial amountof hereditary influence on the development of a variety of traitsthat affect social behavior, including number ability, word fluency,memory, the timing of language acquisition, sentence construction,perceptual skill, psychomotor skill, extroversion and introversion,homosexuality, the timing of first heterosexual activity, and certainforms of neurosis and psychosis, including the manic-depressivesyndrome and schizophrenia.

In most instances, there is a flaw in the results that rendersmost of them less than definitive: Identical twins are commonlytreated more alike by their parents than are fraternal twins. Theyare instructed in a more nearly parallel manner, dressed more alike,and so forth. In the absence of better controls, it is possible thatthe greater similarity of identical twins could, after all, be due toenvironmental influences and not their genetic identity. However, newand more sophisticated studies have begun to take account of thisadditional factor. Loehlin and Nichols (1976), for example, analyzedmany aspects of the environments and performances of 850 sets oftwins who took the National Merit Scholarship test in 1962. The earlyhistories of the subjects, as well as the attitudes and rearingpractices of the parents, were taken into account. The results showedthat the generally more similar treatment of the identical twinscannot account for their greater similarity in general abilities andpersonality traits or even in ideals; goals, and vocationalinterests. It is evident that either the similarities are based insubstantial part on genetic identity or else environmental agentswere at work that remained hidden to Loehlin and Nichols.

My overall conclusion from the existing information is thatHomo sapiens is a typical animal species with reference to thequality and magnitude of the genetic diversity affecting itsbehavior. I also believe that it will soon be within our ability tolocate and characterize specific genes that alter the more complexforms of social behavior. Obviously, the alleles discovered will notprescribe different dialects or modes of dress. They are more likelyto work measurable changes through their effects on learning modesand timing, cognitive and neuromuscular ability, and the personalitytraits most sensitive to hormonal mediation. If social scientists andsociobiologists somehow choose to ignore this line of investigation,they will soon find human geneticists coming up on their blind side.The intense interest in medical genetics, fueled now by new methodssuch as the electrophoretic separation of proteins and rapidsequencing of amino acids, has resulted in an acceleration ofdiscoveries in human heredity that is certain to have profoundconsequences for the study of genetics of social behavior.

I wish now to take up the concerns expressed about humansociobiology in the chapters to follow in Sociobiology and HumanNature. Most have been expressed by other authors in one form oranother before the NEXA conference. I have no desire to rebutspecific points raised by individual authors. This would in any casebe unfair by the ordinary canons of debate, and Sociobiology andHuman Nature surely is a debate. Rather, I want to discuss inbroader terms the ways in which the several intellectual traditionsrepresented so well by the other contributors might be reconciledwith the relatively uncompromising biological approach I have takenup to the present time.

The first area of conflict that can be resolved is the relation ofgenes to culture. Many social scientists see no value in sociobiologybecause they are persuaded that variation among cultures has nogenetic basis. Their premise is right, their conclusion wrong. We cando well to remember Rousseau's dictum that those who wish to studyhumans should stand close, while those who wish to study humanityshould look from afar. The social scientist is interested in theoften microscopic, but important, variations in behavior that almosteveryone agrees are due to culture and the environment. Thesociobiologist is interested in the more general features of humannature and the limitations that exist in the environmentally inducedvariation. He or she is especially interested in the fact that,although all cultures taken together constitute a very great amountof variation, their total content is far less than that displayed bythe remaining species of social animals. By comparing the diagnosticfeatures of human organization with those of other primate species,the sociobiologist aims to reconstruct the earliest evolutionaryhistory of social organization and to discern its genetic residues incontemporary societies. The approach is entirely complementary tothat of the social sciences and in no way diminishes theirimportance--quite the contrary.

Those immersed in the rich lore of the social sciences sometimesreject human sociobiology because it is reductionistic. But almostall of the great advances of science have been made by reduction, inthe form of conjectures that are often bold and momentarilypremature. Theoretical physics transformed chemistry, chemistrytransformed cell biology and genetics, natural selection theorytransformed ecology--all by stark reduction, which at first seemedinadequate to the task. Reduction is a method by which new mechanismsand relational processes are discovered. In the most successful casehistories of postulational-deductive science, propositions areexpressed in forms that can be elaborated into precise, testablemodels. The other side of reduction, the antithesis of the thesis, issynthesis. As the new principles and equations are validated byrepeated testing, they are used in an attempt to reconstitute thefull array of the subject's phenomena. Karl Popper (1974) hascorrectly suggested that philosophical reductionism is wrong but thatmethodological reductionism is necessary for the advancement ofscience. Here is how I tried to summarize the role of sociobiologicalreduction in an earlier review (Wilson, 1977, p. 138):

The urge to be reductionistic is an understandablehuman trait. Ernst Mach [1974] captured it in the followingdefinition: "Science may be regarded as a minimal problem consistingof the completest presentment of facts with the least possibleexpenditure of thought." This is a sentiment of a member of theantidiscipline, impatient to set aside complexity and get on with thesearch for more fundamental ideas. The laws of his subject arenecessary to the discipline above, they challenge and force amentally more efficient restructuring, but they are not sufficientfor its purposes. Biology is the key to human nature, and socialscientists cannot afford to ignore its emerging principles. But thesocial sciences are potentially far richer in content. Eventuallythey will absorb the relevant ideas of biology and go on to beggarthem by comparison.

The strongest redoubt of counterbiology appears to be mentalism.It is difficult--for some it is impossible--to envision the existenceof the mind and the creation of symbolic thought by biologicalprocesses. "The human mind,'' this argument often goes, "is anemergent property of the brain that is no longer tied to geneticcontrols. All that the genes can prescribe is the construction of theliberated brain." But the relation between genes, the brain, and themind is only a practical difficulty, not a theoretical one. Modelshave already been produced in neurobiology and cognitive psychologythat allow at least the possibility of mind as an epiphenomenon ofcomplex but essentially conventional neuronal circuitry.Consciousness might well consist of large numbers of codedabstractions, some fed stepwise through a hierarchy of integratingcenters whose lowest array consists of the primary sense cells,others originating internally to simulate these hierarchies. Thebrain--in Charles Sherrington's (1940) metaphor, the "enchanted loomwhere millions of flashing shuttles weave a dissolving pattern"--notonly experiences scenarios fed to it by the sensory channels but alsocreates them by recall and fantasy. In sustaining this activity, thebrain depends substantially on the triggering effect of verbalsymbols. There is also a reliance on what have been calledplans or schemata-- configurations within the brain,either innate or experiential in origin, against which the input ofthe nerve cells is compared. The matching of the real or expectedpatterns can have one or more of several effects. It can contributeto mental "set," the favoring of certain kinds of sensory informationover others. It can generate the remarkable phenomena ofgestalt perception, in which the mind supplies missing detailsfrom the actual sensory information in order to complete a patternand make a classification. And it can serve as the physical basis ofwill: The mind can be guided in its actions by feedback loops thatlead from the sense organs to the brain schemata to the neuromuscularmachinery and sense organs and back again until the schemata"satisfy" themselves that the correct action has been taken. The mindcould be a republic of alternative schemata, programmed to competefor control of the decision centers, individually waxing and waningin power according to the relative urgency of the needs of the bodybeing signaled through other nervous pathways passing upward throughthe lower brain centers. The mind might or might not workapproximately in such a manner. My point is that it is entirelypossible for all known components of the mind, including will, tohave a neurophysiological basis subject to genetic evolution bynatural selection. There is no a priori reason why any portionof the foundation of human social behavior must be excluded from thedomain of sociobiological analysis.

Some critics have objected to the drawing of analogies betweenanimal and human behavior, especially as it entails the sameterminology to describe phenomena across species. This reservationhas always struck me as insubstantial. The definitions andlimitations of the concepts of analogy and homology have been wellworked out by evolutionary biologists, and it is difficult to imaginewhy the same reasoning cannot be extended with proper care to thehuman species. We already speak of the octopus eye and the human eye,insect copulation and human copulation, and earthworm learning andhuman learning, even though in each of these cases the two speciesare in different superphyla, and the traits listed were independentlyevolved. The questions of interest are in fact the degrees ofconvergence and the processes of natural selection that made theconvergence so close. When biologists compare altruism in thehoneybee worker with human altruism, no one seriously believes thatthey are based on homologous genes or that they are identical indetail. Slavery practiced by Polyergus andStrongylognathus ants resembles human slavery in some broadfeatures and differs from it in others, as well as in most details ofits execution. By using the same term for such comparisons, thebiologist calls attention to the fact that some degree of convergencehas occurred and invites an analysis of all the causes of similarityand difference. There is a Greek-derived term for insectslavery--dulosis--but its usage outside entomology would notonly complicate language but would also slow the very comparativeanalysis that is of greatest interest.

I am most puzzled by the occasional demurral that sociobiologydistracts our attention from the real needs of the world. Thequestions are raised, "How can we worry about the origins of humannature when the nuclear sword hangs over us? When people are starvingin the Sahel and in Bangladesh and political prisoners are rotting inArgentinian jails?" In response, one can answer, "Do we want to know,in depth and with any degree of confidence, why we care? And, afterthese problems have been solved, what then?" The highest goalsprofessed by governments everywhere are human fulfillment above theanimal level and the realization of individual potential. But what isfulfillment, and to what ends can potential be expanded? I suggestthat only a deeper understanding of human nature, which must bedeveloped from neurobiological investigations of the brain and thephylogenetic reconstruction of the species-specific properties ofhuman behavior, can provide humanity with the perspective it requiresto formulate its highest social goals.

The excitement of sociobiology comes from the promise of the roleit will play in this new humanistic investigation. Its potentialimportance beyond zoology lies in its logical position as thebridging discipline between the natural sciences on the one side andsocial sciences and humanities on the other. For years, the chiefspokespersons of the natural sciences to Western high culture havebeen physicists, astronomers, geneticists, and molecularbiologists--articulate and persuasive scholars whose understanding ofthe evolution of the brain and of social behavior was unfortunatelyminimal. Their perception of values and the human condition wasalmost entirely intuitive and hence scarcely better than that ofother intelligent laypersons. Biology has been employed as a sciencethat accounts for the human body; it concerns itself withtechnological manifestations such as the conquest of disease, thegreen revolution, energy flow in ecosystems and the cost-benefitanalysis of gene splicing. Natural scientists have by and largeconceded social behavior to be biologically unstructured and hencethe undisputed domain of the social sciences. For their part, mostsocial scientists have granted that human nature has a biologicalfoundation, but they have regarded it as of marginal interest to theresplendent variations in culture that hold their professionalattention.

In order for the fabled gap between the two cultures to be trulybridged, social theory must incorporate the natural sciences into itsfoundations, and for that to occur biology must deal systematicallywith social behavior. This competence is now being approached throughthe two-pronged advance of neurobiology which boldly hopes to explainthe physical basis of mind, and sociobiology, which aims toreconstruct the evolutionary history of human nature. Sociobiology inparticular is still a rudimentary science. Its relevance to humansocial systems is still largely unexplored. But in the gatheringassembly of disciplines it holds the greatest promise of speaking thecommon language.